Latch



Nov. 1, 1938. H. A. KGNAUFF 2,135,105

LATCH Filed May 12, 1957 v l. ,14 .za

INVENTOR Patented Nov. 1, 1938 PATENT OFFICE LATCH Harry A. Knauff, Pittsburgh, Pa.

application May 12, 1937,

8 Claims.

This invention pertains to latching devices, and more particularly, to automatically tightened devices. In one aspect, my invention deals with improved forms of latching devices which may be used in any suitable association, but which are particularly designed for latching or looking together window sash members. i

I have found that latching devices now on the market may be opened by a sneak thief through the agency of a specialtoolthat is inserted between the window sash rails. The tool is worked in a manner to push latch portions back into an unlatched relationship or to. move the handle portion to obtain the same result. It seems to be a. simple matter for sneak thieves to unlock an ordinary form of window latch.

In view'of the above considerations, it has been an object of my invention to provide a new and improved formof latching device;

Another object of my invention has beento provide a form of latching device that will battle sneak thieves;

Another object of my invention been to provide an improved form oflatchingdevice that may be quickly locked and unlocked by the householder, but that will effectively resist theeiforts of a sneak thief to unlock it;

A further object has been to provide a latch devicethat will automatically tighten when an attempt is made to move it towards an unlocked position when it hasbeen suitably adjusted.

These and many other objects of my invention will appear to those skilled in the art from the following description, the drawing, and the appended claims.

In the drawing: 7

Figure l is a plan section through awindow assembly having associatedtherewith an embodiment of my invention; v

Figure 2 is a vertical sectional elevation taken along the lines 11-11 ofFigure 1;;

Figure 2A is a vertical sectional detail of the keeper of Figures 1 and 2;

. Figure 3 is a vertical section similarto Figure 2-, but showing a modified application of my invention;

Figure 4 is a plan view partially in section of a detail of the embodiment of Figure 3; 1 v

v Figure 5 is a plan view of a modified form of latch keeper;

Figure 6 is a vertical sectional elevation taken along the lines VI-VI of Figure 5;

v Figure 7 is a vertical section detail of a pre ierred formoi latch element; and

mount sleeve I1.

is provided with a horizontally-inwardlyextend- '55 Serial No. 142,145

Figure 8 is a view similar to Figure 7 but showing another preferred. form of latch element.

In carrying out my invention, I preferably provide a type of latch keeper lug and latch keeper shoulder that will cooperatively engage adjacent 5 the unlocked position of the device and will maintain such engaged position for the balance of the locking movement of the device. I also preferably provide the keeper lug and latch shoulder portions with wedge-like surfaces that 10 tend. to draw the Window rails together with a gradually increasing taper or wedge action towards the locking position of the device. However, any suitable form of latch keeper and latch shoulder arrangement may be employed. A fea- 15 ture phase of the'prese-nt invention lies in the provision of what may be termed auxiliary latching elements that are, in eliect, self-latched or automatically tightened when an unauthorized attempt is made to unlock the window.

In the embodiment of rnv invention shown in Figures 1 and'2, I have represented an outer sash rail ID, a glass window ll mounted thereon, and an inner sash rail 12. "It is customary to mount alatch keeper on the outer sash rail l0 and I 25 have shown a keeper member it having an upwardly-extending housing of. somewhat semi-circular-like outline that terminates substantially adjacent its center in a latch keeper lug l4. As shown particularly in Figure 2A, the latch keeper 30 lug i4 is preferably wedge-shaped, tapered, or increasingly inclined from the left to the right in Figure l, or in other words, in the direction of the locking movement. I I

In Figure 1, I have indicated an unlocked posi- 35 tion by the letter A, somewhat central positions by ,the letters B and C, and a fully. locked position by the letter D. I have also provided a bolt or latch housing It having upwardly extending side edges of somewhat semi-circular shape that 0 extend horizontally inwardly. As shown, the keeper housing l3 and the bolt housing it are mounted in position by suitable screws l5 and are in substantial circular alignment. Adjacent the inner edge of the rail l2 and adjacent its center, thehousing I6 is provided with a down.- wardly-projecting bearing sleeve ll. A latch arm I8 is provided with a bearing pivot l9 that extends downwardly and rotatably within the bearing sleeve H. A latchelement 20 or 29, 59 see Figures 7 and 8, is securely attached to the lower end of the pivot pin l9 and holds the latch arm 18 in position with. respect to the The latch element 2%) or 20 ing portion that terminates in an upwardlyextending latch shoulder. The latch shoulder is preferably provided with an entrant portion adextending inwardly of the housing I6, in order to prevent the latch arm I8 from being moved past the maximum locking position D.

Iii-22 are not adjusted. The shoulder of latch element 29, see Figure '7, gives a more gradual closing movement, and is of advantage when the sash rails are to be brought into alignment by the latching device. However, the auxiliary elements IE-ZZ, when adjusted, prevent leverage on arm I8 about the bearing sleeve l7, even when the latch shoulder element 20 and the latch keeper lug I8 have been moved only partially towards the final position D.

Although I have shown the latch keeper lugs I4 and I4 as mounted substantially centrally of the keeper portions I3 and I3, I also contemplate mounting such lugs. somewhateccenshell-like edge or face of the latch housing I 6 is provided with a cam-like surface that in-' creases in divergence or taper outwardly from the full locked position D to the unlocked position A. The arm IB is provided with a downwardly depending lug 2i threaded to receive a the housing IS in position D, the arm I8 can be moved little if any distance to the right of Figure 1, in view of the increasing divergence of tendency of the pin end of the element 22 to increasingly dig into such 'gether more tightly. Another advantage or toparticularly in Figure 1, the outer iliary latching elements to lock the dev pi esent invention and if the armis pulled in either direction, it still maintains the latch keeper lug l4 and the 20 in a locked relation; this is Another embodiment of my invention shown in Figures 3 and 4 provides a modified form of housing I6 that is provided with a slightly-inwardly inclined cam face 24 having a continuousfeet, arm I8 and prevents a sneak thief from pushing the arm I8 upwardly about its pivot point I9 and possibly-snapping it OH. The groove also The taper of the interlocking portions I4 and 20 or 20', can be much greater than heretofore, due to the supplemental action of the auxiliary means I 6-22, and the present form of lock will hold its position regardless of the steepness of the tapered or inclined surfaces.

In Figures 5 and 6, I have shown a stamped or pressed outform of latch keeper I3 having a pended claims.

I claim: 2 1. In a fastening device having a keeper element, a latch housing element,

toward an unlatching position. 7 a r 2. In a fastening device having a keeper ele ment adapted to be mounted on a window sash, a latchhousing' element adapted to be mounted on when said latch is moved toward an unlocked position.

3. In a fastening devices having a keeper element, a latch housing element, a latch member turnably mounted on said housing element and arranged to cooperatively engage said keeper element, said housing element having a cam surface of increasing divergence in one direction thereof, and means cooperatively associated with said latching member and engaging said cam surface for preventing said latch from being unlocked by an unauthorized person.

4. In a fastening device having a keeper ele ment, a'housing element, a latch element turnably mounted upon said housing element and adapted to cooperatively engage said keeper element for locking said housing element and said keeper element together, said housing element having a cam surface of increasing thickness in one direction, an auxiliary latch element associated with said first-mentioned latch element and adapted to cooperatively engage said cam surface.

5. In a fastening device having a keeper element, a latch housing element, a latch element turnably arranged with respect to said housing and adapted to cooperatively engage said keeper element for locking said housing and said keeper element together, said latch element being substantially circular in outline and having an abrupt cam surface adjacent one end thereof and a uniform surface for the balance of its length, so that the fastening device will'be fully locked for the major portion of movement of said latch element with respect to said housing.

6. In a fastening device having a keeper element, a housing element, a latch element turnably arranged with respect to said housing element and adapted to cooperatively engage said keeper element for locking said housing element and said keeper element together, said housing element having a grooved cam surface of increasing thickness in one direction, and an auxiliary latch'element operably arranged with respect to said first-mentioned latch element and adapted to cooperatively engage said grooved cam surface.

7. In a V fastening device adapted to hold a pair of members in a locked association and having a keeper member adapted to be mounted on one of said members and a housing element adapted to be mounted on the other of said members, a bearing on said housing, a latch member pivotally mounted in said bearing and extending outwardly from said latch housing, said latch member having a wedge-shaped latch shoulder portion adapted .to cooperatively-engage said keeper member and lock therewith, an operating arm secured to said latch member and extending beyond said housing element, a cam surface of increasing divergence in one direction associated with said housing element, a lug extending from said operating member, a thumb screw mounted in said lug and adapted to cooperatively engage said cam surface for additionally locking said keeper element and said housing element in associated relation.

8. In a fastening device having a stamped metal keeper element having an eccentrically projecting latch portion, a latch housing element, a latch member pivotally mounted on said latch housing and adapted to turn about said housing substantially the distance of half a circle and to cooperatively engage with said latch portion of said keeper element, said housing element having a cam surface increasing in divergence in the direction of movement employed for unlocking the device, and an element extending from said latch 'element and adapted to cooperatively engage said cam surface for resisting unauthorized attempts to unlock said latch element.

HARRY A. KNAUFF. 

